The present disclosure relates to a nano-structured light-emitting device, and more particularly, to a nano-structured light-emitting device that has a structure that may improve luminescence efficiency.
A semiconductor light-emitting device such as a light emitting diode (LED) or a laser diode (LD) employs electroluminescence, that is, light emission from a semiconductor material according to application of electrical current or a voltage. As an electron and a hole combine at an active layer in the semiconductor light-emitting device, energy amounting to an energy band gap of the active layer, may be emitted in the form of light. Accordingly, a wavelength of light, generated from the light-emitting device, may vary with an amount of the energy band gap of the active layer.
Semiconductor light-emitting devices may be classified into a two-dimensional (2D) light-emitting device, that is, a thin-film light-emitting device in which an active layer is formed in two dimensions, and a three-dimensional (3D) light-emitting device in which an active layer is formed in three dimensions. In a case of the 3D light-emitting device, for example, a light-emitting device with structure including a plurality of nanorods, an active layer is formed in three dimensions. Thus, a light-emitting area of the 3D light-emitting device may be larger in comparison to the 2D light-emitting device. Accordingly, luminescent efficiency may be improved, and colors may be displayed relatively freely throughout the light-emitting device.
Compared to the increase in the light-emitting area, the 3D light-emitting device may provide a relatively low increase in luminescent efficiency. In a case of an LED with a structure, from among 3D structures, of a nano pyramid when electrical current is injected to the LED, the electrical current may be concentrated on the top of the structure. Accordingly, light may be emitted only from the top.
Accordingly, a need exists for an LED with an improved luminescent efficiency.